title: Multi-frequency EDMR applied to microcrystalline thin-film silicon solar cells.
abstract: Pulsed multi-frequency electrically detected magnetic resonance (EDMR) at X-, Q- and W-Band (9.7, 34, and 94GHz) was applied to investigate paramagnetic centers in microcrystalline silicon thin-film solar cells under illumination. The EDMR spectra are decomposed into resonances of conduction band tail states (e states) and phosphorus donor states (P states) from the amorphous layer and localized states near the conduction band (CE states) in the microcrystalline layer. The e resonance has a symmetric profile at all three frequencies, whereas the CE resonance reveals an asymmetry especially at W-band. This is suggested to be due to a size distribution of Si crystallites in the microcrystalline material. A gain in spectral resolution for the e and CE resonances at high fields and frequencies demonstrates the advantages of high-field EDMR for investigating devices of disordered Si. The microwave frequency independence of the EDMR spectra indicates that a spin-dependent process independent of thermal spin-polarization is responsible for the EDMR signals observed at X-, Q- and W-band.
authors.affiliation: Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, D-14195 Berlin, Germany. christoph.meier@fu-berlin.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Meier
authors.forename: Jan
authors.initials: J
authors.lastname: Behrends
authors.forename: Christian
authors.initials: C
authors.lastname: Teutloff
authors.forename: Oleksandr
authors.initials: O
authors.lastname: Astakhov
authors.forename: Alexander
authors.initials: A
authors.lastname: Schnegg
authors.forename: Klaus
authors.initials: K
authors.lastname: Lips
authors.forename: Robert
authors.initials: R
authors.lastname: Bittl
keywords: Electrically detected magnetic resonance; Electron spin resonance; Microcrystalline silicon; Multi-frequency EDMR; Solar cells